Canola: Worms, glyphosate, replant.

Canola: Worms, glyphosate, replant.

10/15/13

Diamond Back Larvae:

Much of the 5 to 6 leaf canola is starting to show evidence of an infestation of the Diamond Back Larvae (worm). This is evident by the "shot holing" of the leaves, and if you look hard enough you can find the worm. (see picture)

Usually the canola plant can take a significant amount of leaf damage so the producer (s) should have time to coordinate the application of glyophosate with the application of insecticide (do them together) to save an application trip.

An infestation left unchecked can eventually reduce leaf area enough to affect plant health or of more concern when the leaf freezes down the worm will then go to the bud and begin to chew on that, (the bud) causing significant yield loss.

Glyphosate application on the canola:

Canola can take glyphosate from emergence to bolting so if the unwanted plants such as volunteer wheat, rye, cheat, weeds, or jointed goat grass are putting so much pressure on the canola at an early stage that the canola stand is threatened you can put it on immediately. Labeling suggests at a reduced rate until 6 leaf stage. (16 ounces instead of 22 ounces if using Monsanto's PowerMax)

However, the longer a field can last, within reason, before glyphosate application (5 to 6 leaf stage) the more unwanted plants will be emerged, the better the initial knock down of those undesirable plants might be. At this stage is also usually a good time to include the insecticide. It just is a judgment call.

Canola replant:

Canola, in the past, has been good at emerging under difficult circumstances. I was in a field today that it was still coming up 3 weeks after planting. However, in some instances this year there have been fields where replanting was probably the best option. Usually because the canola ended up being planted too deep. There are many things to consider with this decision not the least of which is insurance and calendar dates. If replanting check with your insurance carrier and seed distributor for specifics. You might be money ahead.